Java EE 5 Application Components

Java EE 5 simplifies development of enterprise applications by basing
them on standardized, modular components, providing a complete set of services
to those components, and handling many details of application behavior automatically,
without complex programming. Prominent Java EE components include:

Client Application

Web Application

Enterprise Java Bean (EJB)

Connector

Enterprise Application Archive (EAR)

Annotations

Java EE components are packaged separately and bundled into a Java EE
application for deployment. Each component, its related files such as GIF
and HTML files or server-side utility classes, and a deployment descriptor
are assembled into a module and added to the Java EE application. A Java EE application is composed of one or more enterprise bean(s),
Web, or application client component modules. The final enterprise solution
can use one Java EE application or be made up of two or more Java EE applications,
depending on design requirements.

A Java EE application and each of its modules has its own deployment
descriptor. A deployment descriptor is an XML document with an .xml extension
that describes a component’s deployment settings.